It is known to prepare dichlorohydrin by reacting in a reaction zone allyl chloride, water and chlorine in dilute aqueous phase, see e.g., U.S. Pat. Nos. 2,714,121 and 2,714,123, incorporated herein by reference. The term "dichlorohydrin" herein designates the isomers 2,3 dichloro-1-propanol and 1,3 dichloro-1-propanol. The reaction zone effluent may be worked up in different ways to recover the dichlorohydrin therefrom, or may be processed further to convert the dichlorohydrin into derivatives such as epichlorohydrin and/or glycerine.
A disadvantage of the known processes is that substantial amounts of water are used in the reaction zone of the process to reduce formation of undesired by-products, which by-products reduce the overall efficiency of the process, and may complicate purification procedures of the desired product. Such conventional processes after recovery or conversion of the dichlorohydrin result in a substantial volume of an aqueous effluent stream which contains minor amounts of organic impurities. Such effluent requires energy intensive treatment to reduce the amount of organic materials to levels acceptable to be passed to receiving bodies of water such as rivers, lakes and the like. Considerable production cost savings could be effected if the amount of aqueous stream from which the dichlorohydrin is recovered or chemically converted could be significantly reduced. In addition water is an increasingly scarce resource in some locations, and it is highly desirable to be able to reduce the amount of fresh water required to be used in the process, without loss of efficiency. The process according to the invention overcomes such disadvantages.